Gasoline fuel containing substituted diethylenetriamines



-rough idling, engine stalling, and loss of power.

United States Pate 3,231,348 GASOLINE FUEL CONTAINING SUBSTITUTEDDIETHYLENETRIAMINES Eddie G. Lindstrom, Martinez, and Wallace L.Richardson, Lafayette, Calif., assignors to Chevron Research Company, acorporation of Delaware No Drawing. Filed Dec. 7, 1961, Ser. No. 157,834'2 Ciaims. (CI. 44-72) This invention is concerned with motor fuels,and, in partlcular, with gasoline fuels used in spark-ignition in-.ternal combustion engines.

Formation of deposits by gasoline fuels in the induction system of anengine, particularly, in the throttle body section of the carburetor, inthe intake manifold, in the ports and on the undersides of the valves,represents a well-known cause of interference \with the efficientoperation of spark-ignition engines, and is responsible for The loss ofpower is due to throttling of the engine by the deposits in the intakemanifold and ports, and on the valves.

Various additives to be incorporated in gasolines for the purpose ofmitigating formation and build-up of these deposits in the inductionsystem have been proposed in the past. Some of these additives have beenreported to be successful for the purpose, others gave rise to newproblems in engine operation, and a great number of additives proved tobe completely impractical. Therefore, the search for new and effectiveadditives to eliminate deposit formation is still continuing.

It has now been-found that the elimination or at least the reduction ofthese deposits in the induction system of spark-ignition internalcombustion engines can be unexpectedly achieved by incorporating in thegasolines a minor amount, from about 10 to about 1000 parts per eachmillion parts by weight of gasoline, of a certain acyclic aminematerial, apparently exercising a detergentlike action; namely, of astraightchain alkyl or alkenyl substituted diethylenetriamine.

The group of these efiective deposit-reducing organosubstituteddiethylenetriamine derivatives consists of acyclic normal C -Cmonoalkyl-substituted and C C monoalkenyl-substituteddiethylenetriamines. Among them, the C C substituted diethylenetriaminesare particularly efiective. The n-octadecyl-substituted andnoctadecenyl-substituted diethylenetriamines are found to beexceptionally satisfactory. These 'organo-substituteddiethylenetriamines have the general formula:

wherein, in the two occurrences of R one R is hydrogen and the other Ris a radical from the group consisting of normal C C alkyl and normal G-C alkenyl radicals.

Preferably the additive is incorporated into the gasoline in amountswhich may range from about 10 to about 300 ppm. (parts per million),although amounts lower or higher but within the aforementioned 10 to1000 ppm. range may be effectively employed whenever the particularengine conditions would so permit or require. The deposit reduction isobtained both when the additive is incorporated into a lead-freegasoline, i.e. one not compounded wi-th a lead alkyl anti-knock agent,such as tetraethyl lead, and when it is employed in leaded gasoline, forinstance, in one which contains conventional amounts of tetraethyl lead,tetramethyl lead, or other similar lead alkyl agent added to increasethe octane number of the gasoline fuel.

The method of preparation of the aforementioned diethylenetriaminederivatives is not critical. A represen- Patented Jan. 25, 1966 icetative method, carried out in the laboratory to produce sufiicientquantity of the additive for eventual tests in gasoline, involved thefollowing synthesis: 333 g. (1 mol) of octadecyl bromide, 500 ml. (5.1mols) of diethylenetriamine and 500ml. of ethanol were placed in a.flask and heated to reflux temperature. Thereupon 45 g. of sodiumhydroxide in 60 m1. of water was added to the contents of the flask overapproximately 5 minutes. Refiuxing was continued for three hours,whereupon 400 ml. of n-butanol, 400 ml. of benzene and 2 liters of waterwere added, and the resulting mixture was allowed .to

stratify into two layers. The lower aqueous layer was withdrawn anddiscarded. The upper organic layer was washed twice with water, thendried, and the solvent evaporated on a steam plate. The remainingmaterial was analyzed to be N-n-octadecyl diethylenetriamine in a 94%yield.

N-n-octadecenyl diethylenetriamine was prepared by a different method asfollows:

180 g. of the mono-oleyl amide of diethylenetriamine (prepared fromoleic acid and excess of diethylenetriamine) was charged into a pressurebomb of 0.5 liter capacity, into which there were also addedapproximately 30 g. of-Raney nickel and 200 ml. of absolute ethanol. Themixture was subjected to 280 atm. pressure of hydrogen and heated to C.for 6 hours. After cooling, the solution was filtered and the alcoholevaporated. The weight of the recovered N-oleyl diethylenetriamineproduct was 171 g. The equivalent combining weight, determined bytitration, confirmed the nature of the product, which was, in addition,reconfirmed by infra red absorption analysis. The yield ofN-n-octadecenyl diethylenetriamine was better than 99%.

The N-n-octadecyl diethylenetriamine material was subsequently comparedwith other similar polyamines in the glass throttle body engine testspecially developed and designed to observe and to evaluate deposits inthe carburetor. In the test, a glass throttle body is inserted betweenthe venturi section and the cast iron throttle body of a conventionalcarburetor. This glass body represents a section of glass tubing A"thick, about 1 inside diameter and about 2" long. Holes are drilleddiametrically about down from the upper edge of the glass to receive aconventional metal throttle shaft and plate. Both the carburetor and theengine in this test were those of a 6-cylinder Plymouth passengerautomobile.

In each run, the engine was operated on different gasoline fuels at 500rpm. idle, with 5 full throttle, noload accelerations, up to a speed ofabout 3,000 rpm. every 15 minutes during the whole test period. In eachrun, the blowby was piped to the engines induction system as, forinstance, through a pipe connecting the crankcase to the air cleaner ontop of the carburetor. When a run was terminated and the engine stopped,the glass throttle body was removed, and the extent of formation ofdeposits was rated on a scale rangingfrom 1 to 7. A rating of l referredto no deposits at all being formed. A rating of 7 designatedsubstantially complete coating with black, heavy, opaque deposits. Theintermediate ratings indicated various degrees of deposit formationbetween these two extremes. The test gives excellent correlation withthe actual operation of an automobile engine in the field.

In this particular illustrative test, in addition to the N-n-octadecyldiethylenetriamine,other amine materials, i.e., N-dodecyldiethylenetriamine and N-n-dodecyl propylenediamine and were employed inthe previously mentioned effective range of amounts as additives to thesame base gasoline. This gasoline was a commercial regular gasoline,containing about 1.5 ml./gal. of tetraethyl lead, and was typical ofnationally available automotive gasolines. The results of the tests areshown in the following table which indicates the composition of eachfuel (giving the name of the additive), concentration of the additive inparts per million (p.p.m.), the number of runs on each fuel, and theaverage rating of the deposits observed after the test on each fuel.

Glass throttle body test for evalutation of carburetor Dodecyl chain isa propylene tetramer radical.

The data in the above table show the superiority with respect to thereduction of deposits in the carburetor of the acyclic straight-chain(normal) C C substituted diethylenetriamines as compared with likederivatives of acyclic normal substituted diamines and with derivativesof branched-chain substituted diethylenetriamines.

The same representative N-n-o-ctadecyl diethylenetriamine as in Test No.2 in the table hereinabove was tested in a laboratory test in a 1956 V-8Chevrolet automobile engine under conditions which closely simulatedthose of urban and suburban driving. This test lasted 150 hours. Thedisplacement of the engine was 283 cubic inches, and the engine jackettemperature was maintained at 200 C. throughout the test. The gasolineused in this instance was a commercial, premium grade, leaded gasolinecharacterized by a Research octane number of 99.5. This test correlateswell with the operations on the road under conditions apt to causesevere deposit formation in an engine. After each test, with and withoutthe additive, the engine was dismantled, and the ports and undersides ofthe valves were examined and rated on an arbitrarily chosen scale from0, indicating a perfect cleanliness, to 10, indicating very heavydeposit.

In the run employing the aforementioned leaded premium gasoline whichcontained 375 p.p.m. of the diethylenetriamine additive of theinvention, deposits observed on the ports were given a rating of 3.3 andthose observed on the valves were given a rating of 2.3. In the runwithout the additive being present in the gasoline, the ports wereassigned a rating of 4.8 and the valves a rating of 7.8. This againconfirmed the excellent effectiveness of the additive.

To obtain data on the performance of the diethylenetriamine additive ofthe invention in actual operation on the road under average normaldriving conditions, two automobiles, a 6-cylinder Ford with an existingmileage of about 16,000 miles and an 8-cylinder Plymouth with anexisting mileage of about 27,000 miles, were run on a regular leadedbase gasoline compounded with the additive, which Was similar to thegasoline employed in the previously described glass throttle body test.The first automobile ran over 5,000 miles and the second over 2,000miles, using the additive at 500 p.p.m. concentration. The reduction indeposite weight, as observed on dismantling the engines, was determinedto be 50% and 33%, respectively.

In addition to the aforementioned normal long-chain C C monoalkyl andmonoalkenyl derivatives of diethylenetriamine, the gasoline improvedtherewith may contain minor amounts of other conventional fueladditives, provided these amounts and these additives do not detractfrom the detergent and, consequently, deposit removing effect ofdiethylenetriamine derivatives of, the present invention.

Furthermore, to facilitate carrying off the deposits dispersed by thediethylenetriamine materials, in accordance with the invention, an oilsolvent or carrier, such as a light mineral lubricating oil, may beadvantageously employed in amounts from about 0.05 to about 0.5% byvolume and thus will effectively contribute to the reduction of depositsin the area of the intake ports of the engine.

It is desirable to formulate and to dispense the diethylenetriamineadditives of this invention to the trade in the form of concentrateseasy to handle and to blend with the gasoline. Concentrates suitable forshipping and handling both inside and outside refinery premises can beprepared by dissolving the additive in suitable diluents or solventsboiling substantially in the gasoline boiling range. Such solvents are,for instance, hydrocarbon solvents, such as an aromatic hydrocarbonsolvent boiling in the range from about 300 to about 400 F., and any oneof compatible C -C saturated aliphatic alcohols, such as isopropanol,methyl isobutyl carbinol, n-butanol, and the like, as well as mixturesof mutally compatible hydrocarbon solvents and C -C saturated aliphaticalcohols in any desirable proportions to each other, as may be requiredunder the circumstances in each particular case.

We claim:

1. A fuel composition consisting essentially of gasoline and from about10 to about 1000 parts, based on one million parts by weight of saidfuel composition, of an acyclic-substituted diethylenetriamine of thegeneral formula:

wherein, in the two occurrences of R one R is hydrogen and the other Ris a straight-chain hydrocarbon radical from the group consisting ofGig-C20 alkyl and C C alkenyl radicals.

2. An additive concentrate capable of incorporation into gasoline whichis suitable for use in spark-ignition engines, said concentrateconsisting essentially of a solution of an acyclic diethylenetriamine ofthe general for- References Cited by the Examiner UNITED STATES PATENTS2,684,292 7/ 1954 Caron et al. 4474 X 3,011,879 12/1961 Buckmann et al44-72 X 3,031,278 4/ 1962 Buckm-ann et al 4472 X 3,050,043 8/1962Barusch 4472 FOREIGN PATENTS 793,448 4/ 1958 Great Britain.

DANIEL E. WYMAN, Primary Examiner.

1. A FUEL COMPOSITION CONSISTING ESSENTIALLY OF GASOLINE AND FROM ABOUT10 TO ABOUT 1000 PARTS, BASED ON ONE MILLION PARTS BY WEIGHT OF SAIDFUEL COMPOSITION, OF AN ACYCLIC-SUBSTITUTED DIETHYLENETRIAMINE OF THEGENERAL FORMULA: